My take: Existing clergy brotherhoods will see no reason to jump through additional hoops to just keep doing what they are doing. New groups are going to have a hard time convincing the local ROCOR parish to consider it.
And this is really more of an organic process that usually starts with two priests who start inviting each other and their communities to food events, patronal feast days, and the like. Or sometimes parishioners will start these cooperations up. My parish was contacted to invite my parishioners to a local OCF event sponsored by the other parish. We came, we enjoyed the speaker, and we’ll cooperate more.
(EA) – WHAT IS AN INTER-PARISH ASSOCIATION?
Inter-Parish Associations promote communication, camaraderie, and cooperation across Orthodox Christian parishes of all jurisdictions in a given geographical area. They are local (ie. the city/town level) and include both clergy and laity. Their purpose is to break down barriers across Orthodox Christian jurisdictions and, as a unified Orthodox Christian community, witness Christ’s love in local society.